There are two main parts to this project: 1. The New York State (NYS) Study; The objectives are to study - the attitudes of physicians toward Medicare and other health care issues in relation to their political attitudes and career values; the relationships between objective background characteristics, some viewed as sources of socialization, and these attitudes; short-term and long-term changes in attitudes toward Medicare since its passage; the conditions under which these attitudes change; and the effects of these changes on attitudes toward other issues and on attitude structure. The data come from interviews with a probability sample of 1,644 New York State private practitioners, 828 of whom were interviewed three times between 1965 and 1970. 2. The national study. The objectives of this part of the project, which builds on the NYS study, are (1) to describe on a national level the attitudes of physicians, including interns and residents, and medical students toward major issues in the organization of health care (the role of government, financing and method of payment, the organization of practice (e.g., prepaid group practice), the division of labor (e.g., the use of physicians' assistants), controls and reviews), their political attitudes and career values, and (2) to analyze differences in these attitudes between "segments" and age-generations of the profession and according to geographic region. The data come from national samples of 6,500 physicians in all types of professional activity, including interns and residents, and 4,200 medical students, who were interviewed by telephone or completed a questionnaire.